Flexibility and Color Monitoring of Cellulose Nanocrystal Iridescent Solid Films Using Anionic or Neutral Polymers
Flexibility and Color Monitoring of Cellulose Nanocrystal Iridescent Solid Films Using Anionic or Neutral Polymers
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DOI：
10.1021/am506786t
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发表时间：
2015-02-25
影响因子：
9.5
通讯作者：
Bras, Julien
中科院分区：
文献类型：
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作者：
Bardet, Raphael;Belgacem, Naceur;Bras, Julien
硫酸酸化纤维素纳米晶体（CNCs）的一个特性是它们在特定干燥条件下从浓缩悬浮液自组装成彩虹膜的能力。这种彩色薄膜非常脆，这使得它们难以处理或在工业过程中集成。本研究的目标是(i)使用中性聚乙二醇（PEG）生产柔性薄膜，（ii）使用阴离子聚丙烯酸酯（PAAS）调节其颜色。第一部分致力于研究两种聚合物与cnc的物理化学相互作用，使用诸如zeta电位测量，动态光散射（DLS），石英晶体微天平（QCM）和原子力显微镜（AFM）等技术。然后制备了虹彩固体薄膜，并用扫描电子显微镜（SEM）和紫外可见光谱对其进行了表征。采用CNC的薄膜的机械和热性能进行了测量，以评估灵活性的改善。添加10 wt %的PEG使这些薄膜更加灵活（伸长率加倍），颜色得以保留，降解温度提高了近35摄氏度。高达160 μ mol/g（CNC）的PAAS可以通过在可见光谱中产生更窄、更强的颜色（更高的吸收）来调整CNC薄膜的颜色，并具有明显的指纹纹理。
One property of sulfated cellulose nanocrystals (CNCs) is their ability to self-assemble from a concentrated suspension under specific drying conditions into an iridescent film. Such colored films are very brittle, which makes them difficult to handle or integrate within an industrial process. The goal of this study is (i) to produce flexible films using neutral poly(ethylene glycol) (PEG) and (ii) to modulate their coloration using an anionic polyacrylate (PAAS). The first part is dedicated to studying the physicochemical interactions of the two polymers with CNCs using techniques such as zeta potential measurements, dynamic light scattering (DLS), quartz crystal microbalance (QCM), and atomic force microscopy (AFM). Iridescent solid films were then produced and characterized using scanning electron microscopy (SEM) and UVvisible spectroscopy. The mechanical and thermal properties of films incorporating CNC were measured to evaluate improvements in flexibility. The addition of 10 wt % of PEG makes these films much more flexible (with a doubling of the elongation), with the coloration being preserved and the temperature of degradation increasing by almost 35 degrees C. Up to 160 mu mol/g(CNC) PAAS can be added to tune the coloration of the CNC films by producing a more narrow, stronger coloration in the visible spectrum (higher absorption) with a well-pronounced fingerprint texture.